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Unformatted text preview: the two are different with commercial A being higher. Is there any difference between the recall proportions for the two commercials. If so, what is the difference? Ho: p 1- p 2 = D =0 Ha: p 1- p 2 <> D =0 (p-bar 1- p-bar 2 ), the difference found in the two sample proportions Because when Ho is true (p 1 = p 2 ) and the sample sizes are large (n*p & n*(1-p) for both >=5) this test stat is NORMAL with mean (p-bar1 - pbar2) = D = 0 (the difference stated in Ho). = [ p-bar 1 *(1-p-bar 1 )/n 1 + p-bar 2 *(1-p-bar 2 )/n 2 ]^.5 Reject Ho if (p-bar 1- p-bar 2 ) < "value of the normal distribution with cum prob = .025" or if (p-hat 1- p-hat 2 ) > "value of the normal distribution with cum prob = .975"...
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- Spring '07